Carburetor



Patented Jan. 14, 1930 UNITED STATES Pears-1511*?v OFFICE KARL MAYBACH, OF FRIEDRICHSHAFEN, GERMANY, ASSIGNOB. T MAYBACH-MOTOR- ENBYAU GESELLSCHAFT MIT BESCHRAENKTER HAFTUNG, OF FRIEDEICHSHAFEN,

GERMANY CARBURETOR Application led September 20, 1927, Serial No. 220i712., and in 'Germany October 14, 1926. d

My invention relates to carburetors of internal combustion engines and has special reference to carhuretors having a spraying nozzle. Y

Withthese carburetors it is usual to regulate the amount of entering air by means of an air valve or butterfly disc, to regulatethe amount of fuel by means of a needle valve or the like, and to regulate the quantity of the mixture admitted to the engine by means` of a throttle valve or disc.

One main object of my invention is 1mprovement of this regulating mechanism, so

as to be able to do without this throttle valve for regulating the mixture.

Another main object .is the'exact'and easy regulation of the amount of entering fuel.

A further object of myfinvention is to provide. for simple and easily operated means for 2 changing the lrichness of the mixture.

There are other advantages connected with the carburetor constructed in accordance with l my invention which will be pointed out later.

For the purpose of avoiding the throttle valve for controllingtheinixture` I remove the air valve so as to be clo'seto the spraying Y nozzle. A According to my inventlon thefV spraying nozzle which for example may consist of a tube arranged inthe direction of 3" the entering air, is surrounded by an air controlling mechanism. `Thisjmeans that the amount of air and the amountof fuel -both are regulated at the spot where they meet. Thus it is not necessary .to have a third regulating mechanism for the mixture.` 0f course special devices have to bprovideq to make this arrangement as eifectivefas possible.'

My invention is explained best by having reference to the accompanying drawings.

special position ofthe ving mechanism.

. Fig. LLis across section through the upper 'i wing 12 taken on lin'e g'1 -1 of Fig. 1. y

Referring to Fig. 1, arrows A indicate the air flow, arrow G shows the How of the gasof line, and arrow M indicates where the mixture flows to the engine. The-engine has flanges E to which the carburetor is fastened in any well known manner.

The amount lof air entering the engine'is regulated by the distance between lower wing 11 and upper wing 12. These wings may swing around pins 13. In Fig, 1 they are represented in open position; the closed vposition is shown in dotted lines. Two toothed segments 14 serve for transmitting movement vided which allows for'a very small amountof air to pass even lin closed. position of' the wings. Y Y v Y Nozzle tube 16 at its'end has two opposite'- ly arranged holes-18 which are of pear-like shape having their pointed ends towards the engine.

Outer tube 194 closely -tting' over tube 16 is pressed in the' left hand direction by means of spring 20 and is held in position against this spring act-ion by the pressure resulting from lever 21. This lever may swng around pin 22 journaled in the end of ro 23.

The fuel which may be gasoline comes fromY a float chamber 24 which in detail may be constructed in any well known' manner. In the example represented the gasoline Hows in at 25 passing a lioat valve 26 operated by float 27. It then fills the chamber 24 up to level28 from whichthe air passingthrough the opening between the wings v11V and 12 sucks the fuel through tube 16 and through holes 18.

The whole mechanism is operated by moving lever 29. If this lever which-is journaled in pin 3() is moved in the direction of arrow C the carburetor is closed. By means of lever 31 revolving together with lever 29 around pin 30 and being in fixed-relation to lever`29 rod 32 pulls lever 33 so as to revolve around pin 13. Lever 33 isin fixed relation to wing 1l and causes this win to swing inwardly with regardtothe airint e, and wing 11 by means of toothed sgments 14 makes wing 12 also swing inwar y. Lever 29 is connected with cam 34 against which the free end of lever 2l is pressed. Moving lever 29 in the direction of arrow C means adequate turning of cam 34 so that spring 20 by its pressure will move lever 21 in the left hand direction and at the same time tube 19 is shifted over tube 16 so that holes 18 Aare partly or totally covered. depending on the amount of' movement of lever 29.

By means of a thread 35 and a nut 36 rod 23 may be set in' its longitudinal direction to such a position as may be thought adequate with regard to the lever and cam arrangement regulating the fuel access.

Inl Fig. 2 it is Shown how the tube 19 may be slotted so as to give a perfect fitting over tube 16. s

From Fig. 3 a special arrangement of the air intake wings may be seen in its effect. When opening the wings from the closed position at first only a middle portion of the total crosssection is opened as may be seen from Fig. 3. This middle portion is situated exactly around nozzle tube 16. By this arrangement a perfect Carburation is attained even at. low speed of the motor because the vacuum around the nozzle is always sufficient to suck an adequate amount of gaso line due to the-comparatively high speed of the air passing'by the nozzle.

This arrangement consists in the followhe side portions 40 of upper wing 12 are cut off andare loosely journaled at 13. They have apertures 41 into which arms or bolts 41 extend which are in rigid connection with -main and middle wing portion 12. Fixed to this middle portion is a crosspiece 42 which extends over the side portions 40 and in which springs 43 are arranged. These springs press against bolts 44 which again press down the side wing portions40.

Thus, when the wings are opened at first the side portions 40 do not move upwardly but the pressure of springs 43 causes them to be pressed against the downwardly moving lower wing 11. Only the middle portion 12 moves'upwardly so that only 'the middle cross section of the air intake opens. Side portions 40 vare so long following the downward movement of wing 11 against which they are pressed until arms 41 bear against the upper edge of apertures 41. Thereafter these arms 41 are taking the'side portions with the middle portion in its upward movement.

When closing the wings the eect of this arrangement will be the same. Side portions .40 will first touch the lower wing 11 and close c';the outer portion of the air intake leaving open only the middle portion. is then closed by subsequent movement'of the lever arrangement against the pressure of springs I do not want to be limited to' the details described or shown in the drawings because many variations will occur to those .skilled in the art.

VVhatIcla'im is: Y

1. A carburetor for internal l'combustion engines comprising a fuel-nozzle; a mixing chamber; and an air regulatingmechanism; said fuel nozzle and said regulating mechanism being situated closely to eachother;

said regulating mechanismcomprising two wings adapted on adequate. 'movement to open and close said mixing chambenone of said wings heilig subdivided into middle and .side portions, and means for .allowing the side portions to open later than the middle portion. f

2. A carburetor for internal combustion engines comprising a fuelnozzle; a mixing chamber; and an air regulating mechanism; said fuel nozzle and said regulating vmechanism being situated closely 'to eachother; said regulating mechanism comprising two wings adapted on adeguatefmoveinent to open and close said mixing chamber, 4one ofsaid wings bemg subdlvidedmto mlddle and side portlons, and meansfor kallow-ing the .l tions 'to open later and to close earlier than the middle portion.

4.. A carburetor for internal combustion 4engines comprising a fuel nozzle; a mixing' chamber; an air regulatmg mechanism; said fuel nozzle and said regulatin v'mechanism being situated closely to each ot er; said regulating mechanism comprising f two wings adapted on adequate movement to open and close said mixing chamber, one of said wings 4being subdivided into middle and side portions, and means for allowing the side portions to open later and to close earlier than the middle portion; said fuel nozzlecomprising an inner tube having a, hole in its side wall, anouter tube fitting over said inner tube and means for shifting sadouter tube onsaid inner tube; and means for dperating said air regulating mechanism, operating means and said tube shifting means being connected to each other soas to operate simultaneously.

KARL MAYBACH. 

